elegant

SBC_and_a_stick

Clean valves. No need to pull the engine out to blast it in order to clean the DI deposits.

Easy to mod for whatever power you want in the aftermarket by simply upgrading the port injection. Caveat, the ECM might be locked forever.

Thanks! This info is gold. I'm surprised no one is discussing the axial cam. Infinitely adjustable valve lift is actually a killer tech in DOHC, let alone in OHV. This is enough to propel OHV forward and might even topple DOHC. Has anyone noticed the Caddy V8 doesn't even have variable lift? Not even discrete!

Okay, it's a discrete variable lift on intake valves, and then it's also used to shut off the intake and exhaust valves for AFM. It's solenoid operated so probably limited in terms of RPM, but pushrods can't rev much anyway. Think of the cam in cam from the Viper that took it from 500hp to 600hp. You can get that in the C8 now.

I'll take variable phase and lift OHV 6.2L over a 5.5 turbo DOHC that only has variable phase anyday.
https://jalopnik.com/heres-a-close-u...our-1830571473

sunsalem

FWIW, Ferrari sold 8,400 cars during 2017 (last known year of sales).
They artificially keep production low.
God knows how many they would sell if they tried to meet demand.
I think price/value is probably the real key to its success...that, plus the sexy exterior design it has always had.

When going to buy a new car, who worries about replacing the odd blown motor?
That's why warranties exist.

IF someone here is thinking of buying a C8 AND driving it hard after the warranty expires, they are damaging their liver with too many adult beverages.

Rkreigh

the vette has always been about affordable performance but dohc will be needed to meet ever tightening emissions standards and still meet HP goals

varying 4 cams is part of the need and while the pushrod motors have been developed to the zenith possible, there are some inherent advantages to a dohc configuration that cannot be overlooked.

weight, and pacakging and cost are the 3 issues that held back the lt5 c4 zr1 motor from being developed 1996 model year would have done 475 hp without much ado and 500 + is easy target

and yet the engineers can do the same with a pushrod motor to a point with good hot rodding and variable single cam and cyl deactivation

I don't think that stuff would hold up as well lapping at 175 plus though. the dohc engines shine there and durability hasn't been a problem it's back to cost weight and pakcaging

ford saw the light a while back and made the high hp dohc v8s almost as cheap and light as the pushrod motors look at the coyote crate engines.

volume manufacturing will get the price down, just like it would have with the old lt5 I'm sorry, but from an engineering standpoint, dohc turbos and electric will rule the future, like it or not

JerriVette

ConcernedCitizen

sunsalem

If GM doesn't make the base car 500hp, it's a fail IMO.
500 is a good marketing number.

sstonebreaker

Wasn't that the same formula Ford used for the original GT40?

Shaka

More like $700 cost to manufacture. I'm, a suspension guy, so roll couples to me are very important. The geometry compromise required for high CGs forces me to go OHV. My 08 Z is the greatest Vette yet because of the best LS engine yet, the magical 7000 rpm LS7. Outside suppliers caused the head and valve fail problems.


Other Lemans teams complained to the FIA of the advantages of OHV engines and consequently, Corvettes were penalized severely since the C5R. I have C5R square ported heads, timing chain and a cam that gives me reliable 590HP at the rear.
It took from 98 'till 2001 to make the the LS engine decent. The LS6 was the beginning of the super Chevy engine. The C4 GS could beat the C5 right up until the 02 Z. Factory claimed 330 hp, but none ever dynoed < 370Hp.
It out handled the C4 505 hp ZR1 and was a much better car. I owned a 93 ZR1 which I took to Europe. That magic LT4 actually weighed less than the first LS1 by 40lbs. Both coupled to the Tremec T56. The early LS1s turned out to be real disasters. Here is my roadster with a LT4 and LS1. The LS1 is heavier, that's without including the much larger radiator, the two extra gallons of coolant and a huge oil cooler and plumbing. Still would't run cool. Internal design flaws were the culprit. GM revised water jacketing and oil passages and water pump flow.
The C4 LT4 gained 20 hp by it's reverse cooled gear driven water pump system. It took up far less space than the LS1. Much design revision was required including moving the engine forward 3 inches to clear the firewall. Both engines had 420 HP but the LS1 car ended up 220 lbs more because of all the mods required to install the engine.


. If you want real HP, you must start with iron block truck LS engines. There are no DOHC engines that can come close in anyway. If you want a decent Euro car, put a LS7 in it.
http://www.superchevy.com/how-to/090...ngine-history/

ConcernedCitizen

SBC_and_a_stick

On second look, that new 2.7L Silverado engine has integrated exhaust manifolds to meet new emissions standards. That will clobber power substantially. Whatever is gained from new variable valve timing and all the other bits is lost easily with the single port exhaust. Lotus neutered engines with this design starting from about 10 years ago, and looks like Chevy is ready to follow. Shame.

NY09C6

SBC_and_a_stick

It has that benefit for turbo. However, it's used on engines without turbo as well to heat up the catalyst and engine faster. My understanding is that it actually places a heavier burden on the cooling system as the water jackets pick up more of the exhaust heat, though it may serve to keep the catalytic converter alive longer in hi po applications.

NY09C6

sunsalem

Turbo manufacturers need to look at the design F1 is using to reduce lag.

NY09C6

NY09C6

JerriVette

JD_AMG

Let me ask you, if the pushrod engine is so "bad" and not "world beating" then why do world beating supercars like the Ultima GTR use it, when they could use any other engine they wanted? Its not like that car is built with being cheap in mind, its built strictly for performance driving and lap times, yet it uses the "old tech" pushrod V8. Its almost like the engine has some kind of big advantage like weight and size...oh wait it does.
Why does Saleen use a pushrod engine in their S7 super car?
Why do so many one-off supercars use the LSx and not something like a Coyote instead?
Why does a big tuner like Steve Morris build high powered V8s based off LSx architecture (4000+hp)? Why even waste the time when he could strictly build OHC engines?
If DOHC V8s are so much better why are LSx's the most commonly swapped engine on the market, being swapped into S2000s, 240SXs, Skylines, Supras, WRXs, EVOs, Mustangs, Porsche's (911s and 944s), BMWs, Miatas, 350Zs, and just about any other car out there? Why are they replacing their "high tech" DOHC / turbo engine with some low tech pushrod V8, and why more often than not does the car become lighter, handle better, and always end up being faster? Its not cost, they could easily find a junkyard Mod motor, Northstar or Japanese V8 for pretty cheap. Ill give you a hint, those engines dont fit without major cutting, and they are heavy.

Why isn't it common (or even heard of) to swap DOHC V8s into Corvettes?

Again results are what matters, not bench racing about irrelevant details. If a car is running a low 7 minute Nring time and is put held together with popsickle sticks then clearly the engineers are onto something, despite what others are doing.

Ill take whatever engine gives better results, and thus far its been a pushrod V8.

JD_AMG

While the Coyote is vastly better than the previous mod motors it still doesn't stack up to the LSx/LTx. Look a bit up at my previous post, you will see a picture of a Coyote next to an LS3, the Coyote is massive in comparison and heavier, while making less power, less torque and getting worse gas mileage.

If you were to take the LS3 and swap it into a same year Mustang not only would the mustang accelerate quicker, it would brake better and handle better as well - all due to a lighter engine that is more compact, allowing it to be mounted lower in the chassis and closer to the center of the car as well. To top it off the engine itself has a much lower center of gravity as well.

Now think about that for a second, what is so great about a DOHC engine again when we are talking about limited HP production cars? Why would you want something like a Coyote, as great as it is, when the LSx/LTx is that much better?